Welcome to your Quantitative Aptitude Mock Test 31

Three men A, B, and C can do a work in 10, 12, and 15 days respectively. If A works for 3 days, B works for 4 days, and C works for 5 days, what part of the work is done?

Hint

A cistern has two inlets, A and B, and one outlet, C. A can fill the cistern in 6 hours, B can fill the cistern in 8 hours, and C can empty the cistern in 12 hours. If all the three pipes are opened together, how long will it take to fill the cistern?

Hint